The ratio of time taken by A and B to cover a certain distance is 7 : 9. The ratio of their respective speed will be:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 9:7
For a certain distance ratio of speed is inversely proportional to ratio of time
Ratio of time = 7 : 9
hence ratio of speed = 9 : 7